THE NAUTILUS. '.'.") 



never has incised spiral lines. The species are shown to fall into 

 groups according to the sculpture of the embryonic shell ; the char- 

 acters and distribution of all of them are discussed more or less fully, 

 and the following new forms are described : S. a&hmuni, -S. dull!, N. 

 b'tileyi, S. buileyi orcutti, S. fisheri from the United States, and S. 

 nelsoni, S. yoldinani, S. merrill), S. mearnsi from adjacent, slates of 

 Mexico. Six plates of illustrations represent all of the known 

 species and typical examples of the apices ; all being reproduced 

 from photographs. 



There will probably be some difference of opinion about the rank 

 given to the several forms described as species ; but whether they be 

 ultimately ranked as species or subspecies, Mr. Bartsch's careful 

 work in discriminating the numerous forms gives the paper a high 

 value. It ought to be mentioned that the use made of Hyatt's terms 

 of growth is almost throughout erroneous; but as this is in the 

 present case a mere question of descriptive terms, it does not 

 seriously detract from the value of the essay. H. A. P. 



A NEW SPECIES OF AMPIIIDROMUS. By Paul Bartsoh (Smiths. 

 Misc. Col., vol. 47, pp. 292-3). A. gossi, from Mount, Kin Baloo, 

 North Borneo, is described and figured. It is probably a color-form 

 of A. pictus Fult., also described from Mt. Kina Balu, and a very 

 variable species, as the specimens I have seen demonstrate. 

 H. A. P. 



WEST AMERICAN SHELLS. By Josiah Keep, A. M. San Fran- 

 cisco, 1904. Pp. 360, 304 figs. Twenty-three years ago Professor 

 Keep published a modest little book, " Common Sea-shells of Cali- 

 fornia." This was the first successful attempt to popularize the 

 study of American mollusks. It was followed in 1887 by a more 

 extended book, " West Coast Shells," which also met with a cordial 

 welcome from advanced students and beginners in nature study 

 alike. 



The edition of this book being exhausted, Professor Keep has pre- 

 pared a more extended work including descriptions and figures of 

 many more species, and a list of West Coast and Rocky Mountain 

 Mollusca. The descriptions are simply worded, and being supple- 

 mented by several hundred figures in the text, enable the western 

 student to identify and learn something of nearly all the shells likely 



